GB901830A - A new antibiotic danubomycin and a process for its manufacture - Google Patents

Abstract

<PICT:0901830/IV (b)/1> <PICT:0901830/IV (b)/2> A new antibiotic danubomycin effective against bacteria, influenza virus and trichomonas is produced by culturing a danubomycin-producing strain of Streptomyces griseus in an aqueous nutrient medium containing a source of carbon, nitrogen and inorganic salts under surface or submerged aerobic conditions. The temperature of cultivation is 20 to 36 DEG C. and preferably 27 DEG C., the duration 36 to 120 hours. The source of carbon may be carbohydrates such as glucose, saccharose, lactose and starch, or glycerol and mannitol; as nitrogen source there may be used amino acids and mixtures thereof, peptides, proteins and their hydrolysates e.g. peptone and tryptone, meat extracts, aqueous extracts of seed grains, and distillers residues; as inorganic salts there may be used chlorides, nitrates, carbonates or sulphates of the alkali metals, alkaline earth metals, magnesium, iron, zinc or manganese. The antibiotic may be isolated by (a) extraction, (b) adsorption. In the case of (a) the whole broth or the clarified broth may be extracted at a pH above 7.0, and especially pH 8 to 10, with an organic solvent immiscible with water e.g. ethyl acetate. Residual antibiotic is removed from the separated mycelium by extraction with an at least partially water-miscible organic solvent e.g. acetone or butanol or with aqueous acid such as dilute acetic acid. Adsorption may be on active charcoal, activated earth or an ion exchange resin containing carboxyl or sulphonic acid groups, followed by elution with an organic solvent at least partially soluble in water, if desired, with the addition of acids. The antibiotic may be purified by treating the organic extract with aqueous acid having a pH below 5 and re-extracting into a water immiscible organic solvent at a pH above 7.0. The antibiotic danubomycin may be separated into its components B1, B2, B3 and B4 by (a) chromatography (b) counter current distribution between an aqueous solution and an organic solvent immiscible with water. Danubomycin is a red-brown amorphous powder, soluble in alcohol, ketones, esters, chlorinated hydrocarbons and aromatic hydrocarbons; practically insoluble in petroleum ether and water; in alkaline media a colour change to orange red to violet is observed; in ultra violet spectrum it shows an absorption band at 843 mm with shoulder at 260 mm (Fig. 2); the infra red absorption spectrum is shown in Fig. 1; the optical rotation of the hydrochloride is [a ]20D = +223 DEG \sB 8 DEG (C = 0.269 in methanol); it is effective against various pathogenic micro-organisms including Trichomonas foctus; Rf value 0.65 in n-butanol saturated with water (many other systems disclosed); it is distinguished from streptomycin, grisein, rhodomycin, candicidin, streptocin and actidione; it forms salts with inorganic and organic acids e.g. hydrochloric, sulphuric, acetic, propionic, valeric, palmitic, oleic, succinic, citric, mandelic, pantothenic, ascorbic, glutamic and cysteic acids. The antibiotic danubomycin, its components B1, B2, B3 or B4, or a salt thereof, or a mixture of at least two of these substances, in admixture with a pharmaceutical carrier may be used medicinally. The pharmaceutical preparations may be in the form of tablets, dragees, powders, salves, creams, suppositories, solutions, suspensions or emulsions.